Census of Mineral Industries
This report, from the 1992 Census of Mineral Industries, is from the series
of two subject reports. It contains detailed statistics on fuels and
electric energy consumed by mineral industries; the other report is a
general National-level summary. Twelve separate industry reports have been
issued for individual industries or groups of related industries.
Additionally, separate reports have been issued for each of nine geographic
divisions showing statistics by State.
The introduction to the General Summary discusses, at greater length, many
of the subjects described in this introduction. For example, the General
Summary text will discuss the economic significance of the mining sector,
the relation of value added by mining to value added by manufacture, some
of the changes in statistical concepts over the history of the census, and
the valuation problems arising from intracompany transfers between mining
establishments, manufacturing plants, and sales offices and sales branches
of a company.
=> Scope of Census and Definition of Mineral Industries
The 1992 Census of Mineral Industries covers all establishments with one
paid employee or more primarily engaged in mining as defined in the 1987
Standard Industrial Classification (SIC) Manual. This is the system of
industrial classification developed by experts on classification in
Government and private industry under the guidance of the Office of
Information and Regulatory Affairs, Office of Management and Budget. This
classification system is used by Government agencies as well as many
organizations outside the Government.
The SIC Manual defines mining in the broad sense to include the extraction
of minerals occurring naturally: solids such as coal and ores, liquids such
as crude petroleum, and gases such as natural gas. The term "mining" is
used in the broad sense to include quarrying, well operation, milling
(crushing, screening, washing, flotation, etc.), and other preparations
needed to make minerals marketable. Exploration is included as is the
development of mineral properties. Services performed on a contract, fee,
or other basis in the exploration and development of mineral properties are
classified separately but within this division.
Mining operations are classified by industry on the basis of the principal
mineral produced or, if there is no production, on the basis of the
principal mineral for which exploration or development work is in progress.
The recovery of material from culm banks, ore dumps, and other waste
mineral piles is classified in the appropriate mining industry according to
the mineral product recovered.
The crushing, grinding, or other treatment of certain earths, rocks, and
other nonmetallic minerals not in conjunction with mining activities is not
included in this division but is classified as manufacturing. Hauling and
other transportation beyond the mine property and contract hauling (except
out of open pits in conjunction with mining) also are excluded.
Mining operations carried on as secondary activities at manufacturing
establishments (such as clay pits at clay products plants or sand and
gravel operations at ready-mixed concrete plants) are not within the scope
of this census. However, selected data (production workers' wages and
hours; total cost of supplies, fuels, electric energy, and contract work;
and quantity of production for mined products) on such mining activities
have been obtained in the 1992 Census of Manufactures and are included in
the mining reports. They are clearly specified wherever included.
=> Establishment Basis of Reporting
The census of mineral industries covers each mining establishment of firms
with one paid employee or more operating in the United States. A company
operating more than one establishment is required to file a separate report
for each location. A mineral establishment is defined as a single physical
location where mineral operations are conducted.
For oil and gas field operations and for contract services, the basis for
reporting is different from the "establishment" basis used for other types
of mining. Firms operating oil and gas wells, drilling wells, or exploring
for oil and gas for their own account were required to submit a separate
report for each State or offshore area adjacent to a State in which it
conducted such activities. Firms that performed contract services for oil
and gas field operations or for mining establishments were required to
submit one report covering all such activities in the United States and to
include information on receipts for services and production-worker wages
and hours by State. These consolidated reports were then allocated to
State establishments based on the data reported at the State level. The
1992 figures for establishments include the summation of operations for
each State allocated from these nationwide reports.
=> Use of Administrative Records
From a mailout universe of about 28,500 mining establishments,
approximately 11,000 small, single-establishment companies were not mailed
a questionnaire. For these establishments, some employment, payroll, and
receipts data were obtained from the administrative records of other
agencies. Selection of the small establishment nonmail cases was done on an
industry-by-industry basis, and a variable cutoff was used to determine
those establishments for which administrative records were to be used in
place of a census report. This information was then used in conjunction
with industry averages and other information to estimate the statistics for
administrative-record and nonresponse establishments. Fields in files
NC92A1 provide an indication of the extent that these establishments
account for the figures shown. The value of shipments and receipts and cost
of supplies were generally not distributed among specific products and
supplies for these establishments, but were included in the product and
supply "not specified by kind" categories. Overall, establishments for
which administrative-record data were used accounted for less than 2
percent of total value of shipments and receipts.
The industry classification codes included in the administrative-record
files were used for those establishments excused from filing census forms.
Generally, these codes were assigned on the basis of brief descriptions of
the general activity of the establishment. Where the description was
incomplete or where there were relatively fine lines of demarcation among
industries or between mining and nonmining activities, the code assigned to
an establishment could differ from that which would have been assigned on
the basis of more complete product or activity information. Therefore, the
total establishment count should be viewed as an approximate measure. The
counts for establishments with 20 employees or more are far more reliable.
In the 1992 census, as in the 1987, 1982, 1977, and 1972 censuses, data for
single-unit firms without paid employees were excluded. This exclusion had
only a slight effect on industry aggregates for most industries. Data for
firms without employees were included in the 1963, 1958, and 1954 censuses
if they reported more than $500 in (1) value of shipments and receipts, (2)
cost of supplies and purchased machinery, or (3) capital expenditures.
=> Auxiliaries
Statistics for employment and payroll for individual industries and
industry groups also include employment and payroll figures for
administrative offices, warehouses, storage facilities, and other auxiliary
establishments servicing mining establishments. As in previous censuses,
respondents were asked to file separate reports (form ES-9200) for any
separately operated auxiliary establishments. Classification of employment
and payroll data at such auxiliary establishments was based on the mining
establishments served.
=> Industry Classification of Establishments
Each of the establishments covered in the census was classified in 1 of 31
mineral industries in accordance with the industry definitions in the 1987
SIC Manual. An industry is generally defined as a group of establishments
producing the same product or closely related group of products. The
resulting group of establishments must be significant in terms of its
number, value added by mining, value of shipments and receipts, number of
employees, and payroll. Application of these criteria led to the
formulation of 31 mining industries, each assigned a four-digit code. The
classification system also provides broader groups of industries, with 20
three-digit groups and 4 two-digit groups. Within industries, the system
provides for seven-digit products and five-digit product classes. Products
are considered primary to an industry if the first four digits of the
product codes are the same as the industry code. Products whose first four
code numbers differ from the industry code are called secondary products.
To determine the industry classification of an establishment, the seven-
digit products are grouped together according to the first four digits of
the product code. The first four digits of the group of products with the
largest value of production become the industry code for the establishment.
(For mineral service industries, the classification is on the basis of
receipts for services performed.)
In most industries, establishments making products falling into the same
industry category use a variety of processes. Separate statistics are
provided on the various types of operation. Whenever possible, separate
figures are shown for establishments with mines only, mines with
preparation plants, and preparation plants only. Separate figures are
provided by type of mine (underground, open pit, and combination).
Separate statistics also are provided on producing and nonproducing
operations; an establishment being defined as nonproducing if no mineral
products were shipped during the year.
Statistics usually are provided on the production of minerals mined and
used in the same establishment for producing prepared minerals or used
at the producing establishment for fuel.
Differences in the integration of production processes and types of
operation should be considered when relating the general items (employment,
payrolls, value added, etc.) to the product and material data.
=> CENSUS DISCLOSURE RULES
In accordance with Federal law governing census reports, no data are
published that would disclose the data for an individual establishment
or company. However, the number of establishments classified in a specific
industry is not considered a disclosure, so this information may be
released even though other information is withheld.
The disclosure analysis for the State statistics in the tables of this
report is based on the total value of shipments and receipts and capital
expenditures. When the total value of shipments and receipts cannot be
shown without disclosing information for individual companies, the complete
line is suppressed except for capital expenditures. If capital
expenditures alone is a disclosure, only total capital expenditures and
cost of supplies statistics are suppressed. However, the suppressed data
are included in higher-level totals.
=> SPECIAL TABULATIONS
Special tabulations of data collected in the 1992 Census of Mineral
Industries may be requested. The data will be in summary form and subject
to the same rules prohibiting disclosure of confidential information
(including name, address, kind of business, or other data for individual
business establishments or companies) as are the regular publications.
Special tabulations are prepared on a cost basis. A request for a cost
estimate, as well as exact specifications on the type and format of the
data to be provided, should be directed to the Chief, Manufacturing and
Construction Division, Bureau of the Census, Washington, DC 20233-6901.